Jinja2 is used inside of ERP5 (scalability tests).
So we need to explicitely add it, even if we already download it, otherwise it seems buildout keeps it for its own internal use.

This automatically handle lxml installation.

Request the service with the software type pullrdiffbackup.

Real backup are added by request a slave with required parameters:
  hostname="example.org" (just to make think readable for human)
  connection="user@0.0.0.0" (ssh connection string)
  include="/src /home" (space separated directory path to backup)
  frequency="0 0 * * *" (crontab like periodicity string)

Optional parameters are:
  exclude="/home/userA /home/userB" (space separated directory path to not backup)
  sudo="True" (if the server to backup contains a local backupagent_rdiff-backup script which is callable with sudo)

Add a new section ["component"-output] to test the creation of the expected
build output.
The verification is simply done with the "test" command.

The output file are reference as section variable, which allow to reuse the
location in the software profile, and so, prevent harcoding the local directory
path in the software profile.

"-" elect as option caracter
Do not add slave reference by default in Connection Dict for publish

Loosened checks are considered safe enough, and the speedup on many-GB
FileStorage files is significant.

Split line more naturally (don't separate switch from related argument).
Use long options instead of abbreviations.

Also, reduce code duplication.